I am looking for small size(preferably pcb mount) wifi antenna that is directional, more specifically half sphere coverage area. The product I build stays on the ground and I like utilized antenna that is always looking up.
I looked at several ceramic antenna datasheets but could not see one that fits. What type of antenna I should look at?
Based on the response, I thought I should define the problem differently. I have a working product where there is a wifi on top of the product and there are sensitive analogue circuits below the wifi antenna/module. I occasionally get spikes in my analogue circuit (analog has very high gain, about 5M times) when the module is receiving data (TX is fine). Currently, I slapped a EMI absorber on top of my analog stuff and shipped the product, unfortunately this also reduces my wifi coverage/signal by about 10db. In the next version of the product, I like to replace my omnidirectional antenna with a more directional one and avoid signal loss. Hence the question of perfect half sphere of antenna. Now that I know that is not possible, either I need an antenna that has a cone shape coverage or more shielding on Analog which I really like to avoid.